Russia, China and the US have long formed what diplomats call a “strategic triangle” in international affairs. History shows that if two of these states forge a strong bilateral relationship, the third risks being isolated on the big foreign policy issues of the day.

President Richard Nixon’s unexpected “opening to China” in 1972 was the most striking example of how this geopolitical network operates. The rapprochement between Washington and Beijing wrongfooted the Soviet Union, and helped the west to put pressure on the USSR in the late stages of the cold war.

Now it is the US that is being excluded within the triangle. It has taken a hostile approach to both Russia and China over the crisis in Ukraine and alleged Chinese cyber espionage. Moscow and Beijing have responded by engaging in a diplomatic rapprochement that threatens to rebuff the US and complicate western diplomacy.